<!DOCTYPE html>
<html lang="zh-CN">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0, maximum-scale=1, user-scalable=no">
    <meta http-equiv="X-UA-Compatible" content="ie=edge,chrome=1">
    <meta name="author" content="杨宁争">
    <title></title>
    <style>
        .box {
            width: 500px;
            margin-top: 50px;
            margin: 0 auto;
            border: 2px solid black;
        }

        ul,
        li {
            margin: 0;
            padding: 0;
            list-style: none;
        }

        .tou {
            width: 500px;
            height: 40px;
            background-color: black;
        }

        .tou li {
            width: 100px;
            height: 40px;
            text-align: center;
            color: white;
            line-height: 40px;
            float: left;
        }
.footer{
    margin: 0 auto;
    margin-left: 230px;
}
        span {
        display: none;
        }
    </style>
</head>

<body>
    <div class="box">
        <div class="tou">
            <ul>
                <li class="xuanxiang">选项一</li>
                <li class="xuanxiang">选项二</li>
                <li class="xuanxiang">选项三</li>
            </ul>
        </div>

        <div class="footer">
            <span>内容一<br> 内容一</span>

            <span><br>内容二<br> 内容二<br>内容二<br>内容二</span>

            <span><br>内容三<br>内容三<br>内容三</span>




        </div>
    </div>
    <script src="./jquery.js">
    </script>
</body>

</html>
<script>
    $('.xuanxiang').each(function (index) {
        $(this).mouseover(function () {
            $(this).css('background-color', 'gray').siblings().css('background-color', 'black').css(
                'color', '#fff');
            
            $('span').eq(index).css('display', 'block').siblings().css('display', 'none');
        })



    });
</script>